English

Research was undertaken to provide buildings equipped with mechanical exhaust ventilation systems or natural ventilation with reasonable draught-free efficient ventilation. One possible solution for existing detached houses and multi-storey residential buildings is a supply air window. Recent research in Finland shows that, for the best method, about 6.0 dm3/s of outdoor air per light area m2 can be taken in through the wooden construction double-paned window without draught. The incoming air was heated to about 50% of thetemperature difference between the inner and outer air.

A tracer method was developed for the evaluation of workplace ventilation. Nitrous oxide or freon was used as the tracer. The concentration of the tracer gas was measured with an infra-red analyser. The versatility of the tracer technique for industrial hygiene applications was improved by the use of a microcomputer for data calculation, display and storage. Three applications are presented: 1. determination of the capture efficiency of a local exhaust hood, 2. the evaluation of the air leakage of a room, and 3. measurement of the local ventilation rates in a large industrial plant.

This survey describes how external walls and joints are constructed in practice. The paper gives you an opportunity to compare how successful the implementation of airtightness has been in Sweden in comparison with the results presented in the report D2:1983 "Air infiltration control ..." by A Elmroth and P Levin. The survey covers the majority of all Swedish prefabricated single family houses constructed in 1984. All big prefabrication companies are included in the survey.

A reduction of infiltration and ventilation rates by a mere 1% would reduce annual US energy costs by about 300 million dollars. Infiltration and ventilation activities are an important part of the comprehensive energy conservation research policy of the US Department of Energy. The starting point for this policy is an analysis of how energy is used in buildings, starting with an examination of the buildings themselves. Summarizes US research and future activities.

This paper discusses the situation in the Netherlands with respect to air tightness of dwellings and reflects discussions about this in the Dutch Standard Committee on Air Tightness of Buildings. Results of measurements and calculations are given and the considerations of different groups in thediscussion are included. Finally an attempt is made to produce a model for the prediction of air flow rates, infiltration losses and seasonal gas consumption on the basis of air leakage measurements.

This paper reports a case study dealing with the relation between ventilating and airing behaviour and the outside climate. Also the significance of other variables such as preferences with respect to the indoor climate are considered. An indication is found that wind speed correlates, but outside temperature (varying from -3 to +9 degrees C) does not correlate with the length of time the windows in the bedrooms and bathrooms are opened. Rainfall and sunshine also seem to have some influence. The main reason for airing is the opinion that the bedrooms are too warm and not fresh.

Negative pressure inside a building may create adverse or dangerous conditions. Discusses when make-up air is necessary, how need is determined, and how much make-up, with examples.

Complaints related to moisture problems in houses which had been air sealed, led to a study of indoor air quality in 20 weatherized demonstration homes in the Cambridge, Ontario area. 

A previous paper analysed a mathematical model of a non-condensing cavity. This paper extends the analysis of the first paper to analyse the seasonal moisture behaviour of a condensing building cavity. Climate statistics are used to calculate the duration of the winter wet-up period, and a rate of condensation formula is integrated to give total winter condensation. Although engineering design calculations cannot yet be attempted, some illustrative examples are given based on field data. The results give preliminary verification of the model analysed in both papers.